Gas-furnace



(No Model.) 2 SheetsSheet 1.

E. L. CLARK.

GAS FURNACE. No. 364,215. Patented June 7, 1887.

Law

2 Sheets-'-Sheet 2.

(No Model.)

E.L.GLARK.

GAS FURNACE.

No. 364,215. Patented June '7, 1887.

3 M WW UNITED STATES PATENT OFFICE.

EDVARD L. CLARK, OF PITTSBURG, PENNSYLVANIA.

GAS-FURNAC E.

SPECIFICATION forming part of Letters Patent No. 364,215, dated June 7, 1887.

Application filed April 3, 1886. Serial No. 197,601.

To all whom-it may concern:

Be it known that I, EDWARD L. CLARK, of Pittsburg,in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Gas-Furnaces; and I do hereby declare the following to be a full, clear,

and exact description thereof, reference being bad to the accompanying drawings, forming a part of this specification, in whieh- Figure 1 is a side elevation of my improved furnace, part of the side Wall being broken away for clearness of illustration. Fig. 2 is an end view of the furnace. Fig. 3 is an irregular horizontal section on theline x :0 of Fig. 1. Fig. 4 is a vertical section of a part on the line y y of Fig. 3.

Like symbols of reference indicate like parts in each.

The object of the invention is to provide for the construction of an improved and useful metallurgical furnace, in which gas is used as a fuel, and in which the air of combustion is heated before its admixture with the gas, the design of the furnace being to utilize the Waste heat" of the furnace-walls as far as possible without interferingwith the operations of the furnace.

To this end my invention consists, primarily, in the construction of a gas-furnace,with an air-heating flue arranged in recurrent branches, which extend longitudinally in substantially the same horizontal plane under the furnace-bed, the advantages of which, as com- The hearth of the working-chamber is a composite structure, consisting of a lower floor or bed, 5, of tile, which is preferably laid in two or more courses, arranged to break joint the one with the other. Directly above the tile floor 5, back of the wall 3, are courses 6, of

(No model.)

inner sides by partition-walls c and c, and are directly beneath the tile floors 5. At the rear end of the partition-walls c and c the flues a and I) communicate with return-fines a and b, which are in the same horizontal plane with the fines a and b, and are likewise directly beneath the tile floor 5. At the end of the return-flues a and b they communicate with a compound vertical flue, cl (1, which is constituted by a vertical deflecting-plate, 9, set in a space, 10, between the bridge-wall 3 and a vertical wall, 11, in front of the bridge-wall. A tile, 12, set over the space 10 forms the base of the combustion-chamber 4 and the top of the flues d and (1. At the lower part of the flue d an exit-port, 13, through the wall 11, opens into the neck-flue 14 of the-combustion-chamher, and a gas service pipe, 15, discharges thereinto at a suitable point, either above or below the port 13. (See Fig. 4.) When thus constructed, the course of the air to the combustion-chamber is through ports 8,and thence along the flues and b, under the floor 5, to the end of the furnace, and thence back through the return-fines a I) to the partition-plate 9, by which it is deflected upward through the flue d toward the tile 12, and thence down the diving-flue d and through the port 13 into the neck-flue 14, where, mixing with the gas from the pipe 15, combustion ensues, and from the combustion-chamber 4 the heated and burning gases enter the working-chamber 2. In its passage through these flues the air is exposed to a considerable heat from several parts of the furnace. Thus, while in the flues a b and a, b it is in contact with the tile floor 5, which is kept at a high temperature by conduction of heat from the working-chamber 2, and which in turn gives off its heat by radiation to the passing air. The wall 3, being near the combustion-chamber and the heating-chamber and adjacent to the refractory layers 6 and 7, is

normally kept very hot, as is also the tile 12,

which forms the bottom of the combustionchamber, and is thus peculiarly exposed to heat. The air, therefore, in passing through the flues dd,derives additional heat from these parts, and on emerging into the combustionehamber will be raised to a proper temperature to secure good combustion ofthe gas. The peculiar function of the diving-flue d and its port 13, situate near the bottom of the wall 11, is that the air being thus drawn from the lower part of the flue d is first deflected into more intimate contact with the heated tile 12 than if the flue d were absent.

I do not claim, specifically, the arrangement of the fluesrd d and the covering-tile 12.

The advantage of the solid thick bed' 5 6 7 over the ordinary thin metal bed heretofore in common use, in combination with an airheating flue below it, is that while the passing air in the flue is sufficiently heated for purposes of combustion it does not chill the furnace bed and thus impede the metallurgical operations, as is apt to be the case when the metal bottom is used.

I am aware that, broadly speaking, I am not the inventor of a gasfurnace provided with recurrent air-flues underlying the bed of the furnace, nor of a composite furnace-bed, and I disclaim the constructions shown in Letters Patent Nos. 296,398, 296,399, 310,454, 313,348, 179,083, and 9,715; but

WVhat I claim as my invention, and desire to secure by Letters Patent, is

1. The combination, in a gasfurnace, of a combustionchamber, a gas-supply pipe opening into the combustion-chamber, and exterior air-heating fiues,which extend underneath the furnace-bed from the end of the furnace to the EDvVARD L. CLARK.

\Vitnesses:

THOMAS W. BAKEWELL, W. B. CoRwIN. 

